Which one of the followings is an example of ex situ conservation?

The correct answer is Option (1) → Seed bank

Ex situ (off site) conservation protects threatened plants and animals away from their natural habitat; in situ conservation protects them where they live.

Option (1) Seed bank — Correct. Seeds of different varieties are kept viable for long periods in seed banks, away from the habitat.

Option (2) National park — Incorrect. It protects the whole habitat; it is in situ conservation.

Option (3) Sacred groves — Incorrect. These forest patches are protected where they stand by communities; in situ.

Option (4) Wild life Sanctuary — Incorrect. Animals are protected in their own habitat; in situ.

NCERT Extract:
How Do We Conserve Biodiversity? – “… Ex situ Conservation– In this approach, threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be protected and given special care. Zoological parks, botanical gardens and wildlife safari parks serve this purpose. … Seeds of different genetic strains of commercially important plants can be kept for long periods in seed banks.”